<?php
/**
 * CFileValidator class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CFileValidator verifies if an attribute is receiving a valid uploaded file.
 *
 * It uses the model class and attribute name to retrieve the information
 * about the uploaded file. It then checks if a file is uploaded successfully,
 * if the file size is within the limit and if the file type is allowed.
 *
 * This validator will attempt to fetch uploaded data if attribute is not
 * previously set. Please note that this cannot be done if input is tabular:
 * <pre>
 *  foreach($models as $i=>$model)
 *     $model->attribute = CUploadedFile::getInstance($model, "[$i]attribute");
 * </pre>
 * Please note that you must use {@link CUploadedFile::getInstances} for multiple
 * file uploads.
 *
 * When using CFileValidator with an active record, the following code is often used:
 * <pre>
 *  if($model->save())
 *  {
 *     // single upload
 *     $model->attribute->saveAs($path);
 *     // multiple upload
 *     foreach($model->attribute as $file)
 *        $file->saveAs($path);
 *  }
 * </pre>
 *
 * You can use {@link CFileValidator} to validate the file attribute.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CFileValidator.php 2799 2011-01-01 19:31:13Z qiang.xue $
 * @package system.validators
 * @since 1.0
 */
class CFileValidator extends CValidator
{
    /**
     * @var boolean whether the attribute requires a file to be uploaded or not.
     * Defaults to false, meaning a file is required to be uploaded.
     */
    public $allowEmpty=false;
    /**
     * @var mixed a list of file name extensions that are allowed to be uploaded.
     * This can be either an array or a string consisting of file extension names
     * separated by space or comma (e.g. "gif, jpg").
     * Extension names are case-insensitive. Defaults to null, meaning all file name
     * extensions are allowed.
     */
    public $types;
    /**
     * @var integer the minimum number of bytes required for the uploaded file.
     * Defaults to null, meaning no limit.
     * @see tooSmall
     */
    public $minSize;
    /**
     * @var integer the maximum number of bytes required for the uploaded file.
     * Defaults to null, meaning no limit.
     * Note, the size limit is also affected by 'upload_max_filesize' INI setting
     * and the 'MAX_FILE_SIZE' hidden field value.
     * @see tooLarge
     */
    public $maxSize;
    /**
     * @var string the error message used when the uploaded file is too large.
     * @see maxSize
     */
    public $tooLarge;
    /**
     * @var string the error message used when the uploaded file is too small.
     * @see minSize
     */
    public $tooSmall;
    /**
     * @var string the error message used when the uploaded file has an extension name
     * that is not listed among {@link extensions}.
     */
    public $wrongType;
    /**
     * @var integer the maximum file count the given attribute can hold.
     * It defaults to 1, meaning single file upload. By defining a higher number,
     * multiple uploads become possible.
     */
    public $maxFiles=1;
    /**
     * @var string the error message used if the count of multiple uploads exceeds
     * limit.
     */
    public $tooMany;

    /**
     * Set the attribute and then validates using {@link validateFile}.
     * If there is any error, the error message is added to the object.
     * @param CModel $object the object being validated
     * @param string $attribute the attribute being validated
     */
    protected function validateAttribute($object, $attribute)
    {
        if($this->maxFiles > 1)
        {
            $files=$object->$attribute;
            if(!is_array($files) || !isset($files[0]) || !$files[0] instanceof CUploadedFile)
            $files = CUploadedFile::getInstances($object, $attribute);
            if(array()===$files)
            return $this->emptyAttribute($object, $attribute);
            if(count($files) > $this->maxFiles)
            {
                $message=$this->tooMany!==null?$this->tooMany : Yii::t('yii', '{attribute} cannot accept more than {limit} files.');
                $this->addError($object, $attribute, $message, array('{attribute}'=>$attribute, '{limit}'=>$this->maxFiles));
            }
            else
            foreach($files as $file)
            $this->validateFile($object, $attribute, $file);
        }
        else
        {
            $file = $object->$attribute;
            if(!$file instanceof CUploadedFile)
            {
                $file = CUploadedFile::getInstance($object, $attribute);
                if(null===$file)
                return $this->emptyAttribute($object, $attribute);
            }
            $this->validateFile($object, $attribute, $file);
        }
    }

    /**
     * Internally validates a file object.
     * @param CModel $object the object being validated
     * @param string $attribute the attribute being validated
     * @param CUploadedFile $file uploaded file passed to check against a set of rules
     */
    protected function validateFile($object, $attribute, $file)
    {
        if(null===$file || ($error=$file->getError())==UPLOAD_ERR_NO_FILE)
        return $this->emptyAttribute($object, $attribute);
        else if($error==UPLOAD_ERR_INI_SIZE || $error==UPLOAD_ERR_FORM_SIZE || $this->maxSize!==null && $file->getSize()>$this->maxSize)
        {
            $message=$this->tooLarge!==null?$this->tooLarge : Yii::t('yii','The file "{file}" is too large. Its size cannot exceed {limit} bytes.');
            $this->addError($object,$attribute,$message,array('{file}'=>$file->getName(), '{limit}'=>$this->getSizeLimit()));
        }
        else if($error==UPLOAD_ERR_PARTIAL)
        throw new CException(Yii::t('yii','The file "{file}" was only partially uploaded.',array('{file}'=>$file->getName())));
        else if($error==UPLOAD_ERR_NO_TMP_DIR)
        throw new CException(Yii::t('yii','Missing the temporary folder to store the uploaded file "{file}".',array('{file}'=>$file->getName())));
        else if($error==UPLOAD_ERR_CANT_WRITE)
        throw new CException(Yii::t('yii','Failed to write the uploaded file "{file}" to disk.',array('{file}'=>$file->getName())));
        else if(defined('UPLOAD_ERR_EXTENSION') && $error==UPLOAD_ERR_EXTENSION)  // available for PHP 5.2.0 or above
        throw new CException(Yii::t('yii','File upload was stopped by extension.'));

        if($this->minSize!==null && $file->getSize()<$this->minSize)
        {
            $message=$this->tooSmall!==null?$this->tooSmall : Yii::t('yii','The file "{file}" is too small. Its size cannot be smaller than {limit} bytes.');
            $this->addError($object,$attribute,$message,array('{file}'=>$file->getName(), '{limit}'=>$this->minSize));
        }

        if($this->types!==null)
        {
            if(is_string($this->types))
            $types=preg_split('/[\s,]+/',strtolower($this->types),-1,PREG_SPLIT_NO_EMPTY);
            else
            $types=$this->types;
            if(!in_array(strtolower($file->getExtensionName()),$types))
            {
                $message=$this->wrongType!==null?$this->wrongType : Yii::t('yii','The file "{file}" cannot be uploaded. Only files with these extensions are allowed: {extensions}.');
                $this->addError($object,$attribute,$message,array('{file}'=>$file->getName(), '{extensions}'=>implode(', ',$types)));
            }
        }
    }

    /**
     * Raises an error to inform end user about blank attribute.
     * @param CModel $object the object being validated
     * @param string $attribute the attribute being validated
     */
    protected function emptyAttribute($object, $attribute)
    {
        if(!$this->allowEmpty)
        {
            $message=$this->message!==null?$this->message : Yii::t('yii','{attribute} cannot be blank.');
            $this->addError($object,$attribute,$message);
        }
    }

    /**
     * Returns the maximum size allowed for uploaded files.
     * This is determined based on three factors:
     * <ul>
     * <li>'upload_max_filesize' in php.ini</li>
     * <li>'MAX_FILE_SIZE' hidden field</li>
     * <li>{@link maxSize}</li>
     * </ul>
     *
     * @return integer the size limit for uploaded files.
     */
    protected function getSizeLimit()
    {
        $limit=ini_get('upload_max_filesize');
        $limit=$this->sizeToBytes($limit);
        if($this->maxSize!==null && $limit>0 && $this->maxSize<$limit)
        $limit=$this->maxSize;
        if(isset($_POST['MAX_FILE_SIZE']) && $_POST['MAX_FILE_SIZE']>0 && $_POST['MAX_FILE_SIZE']<$limit)
        $limit=$_POST['MAX_FILE_SIZE'];
        return $limit;
    }

    /**
     * Converts php.ini style size to bytes
     *
     * @param string $sizeStr $sizeStr
     * @return int
     */
    private function sizeToBytes($sizeStr)
    {
        switch (substr($sizeStr, -1))
        {
            case 'M': case 'm': return (int)$sizeStr * 1048576;
            case 'K': case 'k': return (int)$sizeStr * 1024;
            case 'G': case 'g': return (int)$sizeStr * 1073741824;
            default: return (int)$sizeStr;
        }
    }
}